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Snap shot of a random typical day as a Trees Management Officer, at the City of London’s Open Space of Hampstead Heath June 2017 05:10 hrs Woke up, fell out of bed, dragged a comb across my head………. well, turned the alarm off before the wife elbows me in the ribs! It’s early and I’m faced with a coffee fuelled drive in to work from deepest darkest sub-urban Suffolk. In to work for 06:50, unlock the park and office, make a brew, fire up the computer to check the weekends e-mails (already checked on the duty work phone to be honest, but I don’t let the better half know I’m keeping an eye on work at the weekend) The office is a porta-cabin in the Arb yard at a Victorian park in North West London. I’ve been employed here variously since the hazy summer of 1985, at first as a horticultural apprentice, then as a climbing Arb before becoming team supervisor then the job morphing in to a TMO. I run an in-house Arb team of four, we inspect our tree population using Arbortrack within a risk sequencing system. We sometimes cut our trees, we sometimes airspade our trees, we sometimes talk to the locals about our/their trees. Anything tree related, from safety to ecology, is basically our remit. The Heath has approximately 20,000 trees and sprawls out across parts of the London Boroughs of Barnet, Camden & Haringey but the trees have no conservation area or tree preservation orders. 07:30 hrs This particular morning I’m off to Queens Park (one of our satellite parks) over in the north east of the London Borough of Brent to check for the presence of Oak Processionary Caterpillars. There are only a couple of dozen oaks here out of the local 580 tree population, and the critters have been sniffing them out for the last couple of years. During a walk over inspection I pick up on a few new potential Massaria affected London plane branches in the park, so note them for climb inspection and potential removal by the team possibly this week or later in the month. 09:30 hrs Catch a breakfast in the park café, chatting to the (fleet, constabulary and park) manager about vehicle & equipment (mewp) disposal. 10:00 hrs Drive back over to Hampstead. There’s a phone call report of a large branch failure on an Ash near to property on the other side of the heath. Turn up, check on the tree failure (Inonotus hispidus decay at an old pruning wound) Clear the branch failure and note that the tree should go on to our priority tree works list for reduction, as its lost another branch in the past probably also due to I. hispidus. 11:30 hrs Meet up with my boss in Highgate to sign off the team’s end of year performance/development reviews……….blinkin paper work ! 12:00 hrs Back to the yard. I order in some climbing & rigging equipment & vehicle parts for the team Land Rover. Send a few e-mails off. Sample of emails include…… Brent Tree Officer (about OPM) My boss (about a work experience enquiry from France) In house Ecologist (asking me for a fungi ident) My boss (about some training issues) A student (about why dressing parts of one of our trees in tin foil for an photography project, is not the type of thing we would ideally condone) Boss again (about team members sickness trigger level meeting) Grab a coffee 13:30 hrs Catch up with team out on site where they are clearing & lifting a few trees where the horticultural team are building a new stumpery. 14:45 hrs Back to the office. Putting together a list of veteran trees to work on over the next 18 months as part of an Ecology, Conservation & Trees team annual work plan. 16:00 hrs Up to the head office on the Archway Road to catch up with the admin team (about receipts & purchase card issues......blinkin admin) then the boss to have the bi-monthly 121 meeting, talking budgets, work plans and stuff. 17:30 hrs – 20:00 hrs Finish the day up by having a look at a few unread threads at the UKTC, LTOA & Arbtalk forums Chatting on line to an American Arb about Subterranean Root Girdles ! Edit some photographic images for my archives. tree day done..........now where's me beer !

With the 30th anniversary of the hurricane approaching and having visited many sites with old trees both here and abroad over the last 10 years, I have been moved to ponder how many veteran/ancient trees were perhaps lost to us in the UK on that fateful night in 1987. The great storm brought gusts of up to 94mph across London, leading to 15 million trees being damaged and/or destroyed throughout the UK and 18 people losing their lives. Six of the seven eponymous oaks in Sevenoaks were toppled and the National Pinetum at Bedgebury in Kent lost at least 30% of the National Conifer Collection. Having witnessed the ferocity of that tempest during the evening and throughout the night, I returned to work the following morning, weaving my car through the woody debris of the aftermath. I was unsure what to expect once I arrived at the gates of the north London open space of Hampstead Heath where I was based as a horticultural apprentice. Sadly, I was to witness devastation. Observations over 30 years suggest that there are multiple outcomes for veteran trees exposed to severe weather events. We see destruction, dysfunction and decline in the roots, trunks and canopy of old trees. However, we often, with time, also see rejuvenation. Hampstead Heath storm damage, 1987. A total of 647 trees were damaged at Hampstead Heath in October 1987 with 483 of those completely uprooted – and somewhat surprisingly, only four of those were veterans (250 years old or above). I have talked with other tree managers/ officers/ecologists across open-space sites in the south-east of the UK (especially those with large numbers of ancient/ veteran trees), and it turns out that old hollow trees came through the storm largely unscathed. #jscode# Most of these sites were extensively surveyed post storm, and thanks to the efforts of those surveyors, we have valuable information about the species and age of trees impacted by the storms. At Hampstead, all the damaged and toppled trees within the site compartments were recorded and measured. The map (below) shows a section of Windsor Great Park which was compiled by Ted Green post storm. It records oak trees lost (red dot), oak canopy damage (red circle), beech trees lost (blue circle), sweet chestnut lost (green triangle), lime trees lost (orange triangle) and various other species. Windsor Great Park lost none of the ancient hollow trees at the roots; only partial canopy and branches above the hollow trunks were affected. Perhaps there are reasons which can be debated for this, including (natural and unnatural) propping, shorter stout retrenching canopies and protection from the wind by taller younger neighbouring trees, but the hollow nature and flex in movement of these veterans played a fundamental part in their on-going survival. Ted recounted to me one particular old beech at Windsor which was hollow from the ground right up to its canopy framework; it stood firm whilst the younger sweet chestnuts in the plantation around it succumbed to the wind and all fell like dominos. Richmond Park lost none of its famous named veterans/ancients like the 750-year-old Royal Oak. Rangers who were working at Burnham Beeches and Ashtead Common at the time of the storm recall that none of their hollow old pollards collapsed or toppled. The low numbers of veteran trees lost at these five sites amongst the thousands of damaged and uprooted trees strongly suggests that veterans which are hollow and/or retrenched with shorter, compact canopy sails can and do withstand significant storms like the one in 1987. The following 3 trees are good examples of Ancient/veteran trees that came through the storm largely unscathed. Above; The Royal Oak, Richmond Park Above; Pollarded beech, Burnham Beeches Above; King Offa's Oak, Windsor Great Park The case studies that follow examine two Hampstead Heath veterans that survived the storm. Both trees have benefited from management intervention. Case study 1: The Bandstand Oak In the heart of a north London Victorian park known as Golders Hill sits a well-known landmark tree called the Bandstand Oak (above). Thousands of people have sat in their deckchairs during the summer months over many decades listening to jazz and watching clowns hosted at the park’s performing stage. The oak tree is thought to be approximately 450 years old and has a girth of 6.75m. I first became aware of this particular tree as a child when my family visited the park and Hampstead Heath around the late ’70s and early ’80s. The two images (below) taken in 1900 and 1975 appear to show the tree had been thinned and/ or pruned but they may also reveal what years later I would understand to be early natural retrenchment. #jscode# It is an imposing landscape tree that is a relic of a less urban time in the site’s history. It had changed little in terms of aesthetics and health since the beginning of the 1900s up to when the storm struck. I take many images of trees daily, both at work and in my leisure time, so it is a little frustrating that I didn’t capture any images of this tree in the immediate aftermath of the storm. We didn’t have digital cameras back then and were too busy clearing up damaged trees across the site and unblocking the roads outside. The tree is open-grown and sits on a hill so the wind had complete access to wreak havoc on the canopy. I suspect that the oak was then, as now, colonised by the brown rot decay of the chicken of the woods (Laetiporus sulphureus) and this would have had a significant influence on the oak being dismantled branch by branch as opposed to being completely uprooted. The ferocity of that storm and the heartwood decay resulted in the upper crown becoming smashed and fractured. The crown was subsequently cleaned and made ‘safe’ by being reduced back to almost just the trunk and stubbed main scaffolds. At that time, the knowledge of retaining as much photosynthetic material as possible whilst reducing a veteran tree (post storm or otherwise) was perhaps in its infancy and the guys on the tree team had a very long list of trees to clear up. Above; Bandstand Oak 1975 Although the 2 images of the tree out of leaf above were taken several years after the work, the tree’s winter frame allows us to see the severity of the reduction carried out at the time of the storm in comparison to the tree as it was in the earlier photographs. Clearly visible in the sunrise image is how well the tree has responded to the ‘topping’ over that time. The reiterated branch framework has developed well in the last 30 years due to the oak’s vitality. The only canopy work done in the last 15 years has been to retrieve a succession of lost kites and the removal and/or partial removal of significant-sized dead branches above static park benches. With time and an understanding of the niche habitat that retained dead branches provide for biodiversity, we managed the risk of the sitting target by moving the ‘static’ benches and erecting a metal fence which in keeping with the park’s boundary fencing. This has also had the benefit of stopping young aspiring monkeys who loved to climb the old tree and were damaging the bark and lower branches. Those future potential arborists still have younger trees to climb on as several young oaks were planted before and after the storm to continue the oak population that has been part of the local historic treescape for centuries. The tree does suffer root issues which can be seen in the decline on one side of the canopy. This is due in part to the close-cropped grass-mowing regime and the compaction caused by heavy foot fall – this is a popular, well-used park. The demand for space during good weather and events held at the bandstand limits the total area of roots we can protect with the fencing. The tree has had on-going applications of foliar microbial compost tea which it is hoped will benefit the health of the oak and the soil below. It remains an imposing landscape feature tree now and hopefully for many decades to come. Case study 2: The hollow beech This hollow beech has a girth of 5.52m girth at 2m. It mostly withstood the 1987 storm and also subsequent arson attacks. It has been hollowed out by the activity of bacteria and various decay fungi over the last 100 years or so. The storm stripped bare most of the upper canopy, leaving no upper trunk beyond 13m and only six of the main scaffold branches that make up the remaining framework. Surprisingly for beech, over the next three decades the tree has reiterated a new canopy, forming dozens of new ‘young trees’ on the upper branch surfaces. The beech is subject to a reduction cycle where it is reduced in height by 1–2m every five years with the intention of keeping the canopy from protruding out beyond its neighbours and having the younger, weakly attached pole regrowth exposed to wind load. (Rare, non black and white image of the author up in the canopy of the hollow beech picture 3 below) Habitat created by natural and unnatural events Storms of course are not the only major risk to veteran trees. Although the veteran pollard oaks at Ashtead Common largely survived the great storm of 1987, unlike the maiden beech and other species in the locality that were swept over in their hundreds, many of them succumbed to a large (bracken) fire in 1990 which damaged or destroyed over a hundred of the old pollards. Those trees are no longer alive. However, they still provide valuable habitat as standing dead wood volume for a wide range of saproxylic invertebrates, fungi, bats and birds. Maintaining these standing dead wood volumes is an important aspect of biodiversity management. For more information on this habitat-type creation and retention, see the authors article ‘Standing dead trees in the urban forest’ in the ARB Magazine 166 (autumn 2014). Storms, Pruning and other events like mechanical injuries help create veteran features and improve potential habitat value for biodiversity. As long as assessment of the loss of part of the tree can determine that there is no adverse effect on its stability, these tears, branch socket cavities and impact wounds can be retained as future habitat. The Bandstand Oak has been a regular host to kestrels and to smaller avian species like nuthatch and blue tits. Cavities in the trunk and branch unions from pruning and natural branch tear outs provide fine habitat potential that is utilised by successive generations of birds and bat species. The Moccas Park oak (below) has been left unmanaged because it sits in a very rural landscape with low risk to site visitors whereas the Hampstead oak pictured (which is colonised by Fistulina hepatica) has been lightly reduced to reduce load on its canopy sail as it sits in an urban open space with many visitors. Above; The Moccas Park Oak Above; Hampstaed Oak failure. Fistulina hepatica colonisation Fungi species like Laetiporus sulphureus, Fistulina hepatica and Buglossoporus quercinus are just some of the organisms at play in the slow decay process of wounds ; species like owls eventually take advantage of these sites and colonise them. The decay process can take many decades in temperate areas like northern Europe. Bees, woodpeckers, parakeets and other species all accelerate the process of cleaning out cavities for their own use and future use by larger inhabitants. I give great thanks to Ted Green who continues to inspire and also helped with information regarding the veteran and ancient trees at Windsor Great Park before and after the great storm. This article was originally published in the ARB MAgAzIne | Issue 178 Autumn 2017 View full article

With the 30th anniversary of the hurricane approaching and having visited many sites with old trees both here and abroad over the last 10 years, I have been moved to ponder how many veteran/ancient trees were perhaps lost to us in the UK on that fateful night in 1987. The great storm brought gusts of up to 94mph across London, leading to 15 million trees being damaged and/or destroyed throughout the UK and 18 people losing their lives. Six of the seven eponymous oaks in Sevenoaks were toppled and the National Pinetum at Bedgebury in Kent lost at least 30% of the National Conifer Collection. Having witnessed the ferocity of that tempest during the evening and throughout the night, I returned to work the following morning, weaving my car through the woody debris of the aftermath. I was unsure what to expect once I arrived at the gates of the north London open space of Hampstead Heath where I was based as a horticultural apprentice. Sadly, I was to witness devastation. Observations over 30 years suggest that there are multiple outcomes for veteran trees exposed to severe weather events. We see destruction, dysfunction and decline in the roots, trunks and canopy of old trees. However, we often, with time, also see rejuvenation. Above - Hampstead Heath storm damage, 1987. A total of 647 trees were damaged at Hampstead Heath in October 1987 with 483 of those completely uprooted – and somewhat surprisingly, only four of those were veterans (250 years old or above). I have talked with other tree managers/ officers/ecologists across open-space sites in the south-east of the UK (especially those with large numbers of ancient/ veteran trees), and it turns out that old hollow trees came through the storm largely unscathed. Most of these sites were extensively surveyed post storm, and thanks to the efforts of those surveyors, we have valuable information about the species and age of trees impacted by the storms. At Hampstead, all the damaged and toppled trees within the site compartments were recorded and measured. #jscode# The map below shows a section of Windsor Great Park which was compiled by Ted Green post storm. It records oak trees lost (red dot), oak canopy damage (red circle), beech trees lost (blue circle), sweet chestnut lost (green triangle), lime trees lost (orange triangle) and various other species. Windsor Great Park lost none of the ancient hollow trees at the roots; only partial canopy and branches above the hollow trunks were affected. Perhaps there are reasons which can be debated for this, including (natural and unnatural) propping, shorter stout retrenching canopies and protection from the wind by taller younger neighbouring trees, but the hollow nature and flex in movement of these veterans played a fundamental part in their on-going survival. Ted recounted to me one particular old beech at Windsor which was hollow from the ground right up to its canopy framework; it stood firm whilst the younger sweet chestnuts in the plantation around it succumbed to the wind and all fell like dominos. Richmond Park lost none of its famous named veterans/ancients like the 750-year-old Royal Oak. Rangers who were working at Burnham Beeches and Ashtead Common at the time of the storm recall that none of their hollow old pollards collapsed or toppled. The low numbers of veteran trees lost at these five sites amongst the thousands of damaged and uprooted trees strongly suggests that veterans which are hollow and/or retrenched with shorter, compact canopy sails can and do withstand significant storms like the one in 1987. Above left; a sample of Ted Green’s post-storm map assessing the damage to trees in Windsor Great Park. Above right: Veteran tree sites in the south-east. (Map data © Google) Above left; the Royal Oak in Richmond Park Above centre; pollard at Burnham Beeches. Above right; King Offa’s Oak in Windsor Great Park, all veterans that withstood the 1987 storm. The case studies that follow examine two Hampstead Heath veterans that survived the storm. Both trees have benefited from management intervention. Case study 1: The Bandstand Oak In the heart of a north London Victorian park known as Golders Hill sits a well-known landmark tree called the Bandstand Oak (above). Thousands of people have sat in their deckchairs during the summer months over many decades listening to jazz and watching clowns hosted at the park’s performing stage. The oak tree is thought to be approximately 450 years old and has a girth of 6.75m. I first became aware of this particular tree as a child when my family visited the park and Hampstead Heath around the late ’70s and early ’80s. The two images below taken in 1900 and 1975 appear to show the tree had been thinned and/ or pruned but they may also reveal what years later I would understand to be early natural retrenchment. It is an imposing landscape tree that is a relic of a less urban time in the site’s history. It had changed little in terms of aesthetics and health since the beginning of the 1900s up to when the storm struck. I take many images of trees daily, both at work and in my leisure time, so it is a little frustrating that I didn’t capture any images of this tree in the immediate aftermath of the storm. We didn’t have digital cameras back then and were too busy clearing up damaged trees across the site and unblocking the roads outside. The tree is open-grown and sits on a hill so the wind had complete access to wreak havoc on the canopy. I suspect that the oak was then, as now, colonised by the brown rot decay of the chicken of the woods (Laetiporus sulphureus) and this would have had a significant influence on the oak being dismantled branch by branch as opposed to being completely uprooted. The ferocity of that storm and the heartwood decay resulted in the upper crown becoming smashed and fractured. The crown was subsequently cleaned and made ‘safe’ by being reduced back to almost just the trunk and stubbed main scaffolds. At that time, the knowledge of retaining as much photosynthetic material as possible whilst reducing a veteran tree (post storm or otherwise) was perhaps in its infancy and the guys on the tree team had a very long list of trees to clear up Although the images at the top of the article and above were taken several years after the work, the tree’s winter frame allows us to see the severity of the reduction carried out at the time of the storm in comparison to the tree as it was in the earlier photographs. Clearly visible in the sunrise image is how well the tree has responded to the ‘topping’ over that time. The reiterated branch framework has developed well in the last 30 years due to the oak’s vitality. The only canopy work done in the last 15 years has been to retrieve a succession of lost kites and the removal and/or partial removal of significant-sized dead branches above static park benches. With time and an understanding of the niche habitat that retained dead branches provide for biodiversity, we managed the risk of the sitting target by moving the ‘static’ benches and erecting a metal fence which in keeping with the park’s boundary fencing. This has also had the benefit of stopping young aspiring monkeys who loved to climb the old tree and were damaging the bark and lower branches. Those future potential arborists still have younger trees to climb on as several young oaks were planted before and after the storm to continue the oak population that has been part of the local historic treescape for centuries. The tree does suffer root issues which can be seen in the decline on one side of the canopy. This is due in part to the close-cropped grass-mowing regime and the compaction caused by heavy foot fall – this is a popular, well-used park. The demand for space during good weather and events held at the bandstand limits the total area of roots we can protect with the fencing. The tree has had on-going applications of foliar microbial compost tea which it is hoped will benefit the health of the oak and the soil below. It remains an imposing landscape feature tree now and hopefully for many decades to come. #jscode# Case study 2: The hollow beech This hollow beech has a girth of 5.52m girth at 2m. It mostly withstood the 1987 storm and also subsequent arson attacks. It has been hollowed out by the activity of bacteria and various decay fungi over the last 100 years or so. The storm stripped bare most of the upper canopy, leaving no upper trunk beyond 13m and only six of the main scaffold branches that make up the remaining framework. Surprisingly for beech, over the next three decades the tree has reiterated a new canopy, forming dozens of new ‘young trees’ on the upper branch surfaces. The beech is subject to a reduction cycle where it is reduced in height by 1–2m every five years with the intention of keeping the canopy from protruding out beyond its neighbours and having the younger, weakly attached pole regrowth exposed to wind load. Habitat created by natural and unnatural events Storms of course are not the only major risk to veteran trees. The veteran pollard oaks at Ashtead Common (below) largely survived the great storm of 1987, unlike the maiden beech and other species in the locality that were swept over in their hundreds, many of them succumbed to a large (bracken) fire in 1990 which damaged or destroyed over a hundred of the old pollards. Those trees are no longer alive. However, they still provide valuable habitat as standing dead wood volume for a wide range of saproxylic invertebrates, fungi, bats and birds. Maintaining these standing dead wood volumes is an important aspect of biodiversity management. For more information on this habitat-type creation and retention, see the authors article ‘Standing dead trees in the urban forest’ in the ARB Magazine 166 (autumn 2014). Storms, pruning and other events like mechanical injuries help create veteran features and improve potential habitat value for biodiversity. As long as assessment of the loss of part of the tree can determine that there is no adverse effect on its stability, these tears, branch socket cavities and impact wounds can be retained as future habitat. The Bandstand Oak has been a regular host to kestrels and to smaller avian species like nuthatch and blue tits. Cavities in the trunk and branch unions from pruning and natural branch tear outs provide fine habitat potential that is utilised by successive generations of birds and bat species. The Moccas Park oak, below left, has been left unmanaged because it sits in a very rural landscape with low risk to site visitors whereas the Hampstead oak pictured below right (which is colonised by Fistulina hepatica) has been lightly reduced to mitigate load on its canopy sail as it sits in an urban open space with many visitors. Fungi species like Laetiporus sulphureus, Fistulina hepatica and Buglossoporus quercinus are just some of the organisms at play in the slow decay process of wounds ; species like owls eventually take advantage of these sites and colonise them. The decay process can take many decades in temperate areas like northern Europe. Bees, woodpeckers, owls and other species all accelerate the process of cleaning out cavities for their own use. . I give great thanks to Ted Green who continues to inspire and also helped with information regarding the veteran and ancient trees at Windsor Great Park before and after the great storm. This article was originaly published in the ARB MAgAzIne | Issue 178 Autumn 2017 View full article

With the 30th anniversary of the hurricane approaching and having visited many sites with old trees both here and abroad over the last 10 years, I have been moved to ponder how many veteran/ancient trees were perhaps lost to us in the UK on that fateful night in 1987. The great storm brought gusts of up to 94mph across London, leading to 15 million trees being damaged and/or destroyed throughout the UK and 18 people losing their lives. Six of the seven eponymous oaks in Sevenoaks were toppled and the National Pinetum at Bedgebury in Kent lost at least 30% of the National Conifer Collection. Having witnessed the ferocity of that tempest during the evening and throughout the night, I returned to work the following morning, weaving my car through the woody debris of the aftermath. I was unsure what to expect once I arrived at the gates of the north London open space of Hampstead Heath where I was based as a horticultural apprentice. Sadly, I was to witness devastation. Observations over 30 years suggest that there are multiple outcomes for veteran trees exposed to severe weather events. We see destruction, dysfunction and decline in the roots, trunks and canopy of old trees. However, we often, with time, also see rejuvenation. Above - Hampstead Heath storm damage, 1987. A total of 647 trees were damaged at Hampstead Heath in October 1987 with 483 of those completely uprooted – and somewhat surprisingly, only four of those were veterans (250 years old or above). I have talked with other tree managers/ officers/ecologists across open-space sites in the south-east of the UK (especially those with large numbers of ancient/ veteran trees), and it turns out that old hollow trees came through the storm largely unscathed. Most of these sites were extensively surveyed post storm, and thanks to the efforts of those surveyors, we have valuable information about the species and age of trees impacted by the storms. At Hampstead, all the damaged and toppled trees within the site compartments were recorded and measured. The map below shows a section of Windsor Great Park which was compiled by Ted Green post storm. It records oak trees lost (red dot), oak canopy damage (red circle), beech trees lost (blue circle), sweet chestnut lost (green triangle), lime trees lost (orange triangle) and various other species. Windsor Great Park lost none of the ancient hollow trees at the roots; only partial canopy and branches above the hollow trunks were affected. Perhaps there are reasons which can be debated for this, including (natural and unnatural) propping, shorter stout retrenching canopies and protection from the wind by taller younger neighbouring trees, but the hollow nature and flex in movement of these veterans played a fundamental part in their on-going survival. Ted recounted to me one particular old beech at Windsor which was hollow from the ground right up to its canopy framework; it stood firm whilst the younger sweet chestnuts in the plantation around it succumbed to the wind and all fell like dominos. Richmond Park lost none of its famous named veterans/ancients like the 750-year-old Royal Oak. Rangers who were working at Burnham Beeches and Ashtead Common at the time of the storm recall that none of their hollow old pollards collapsed or toppled. The low numbers of veteran trees lost at these five sites amongst the thousands of damaged and uprooted trees strongly suggests that veterans which are hollow and/or retrenched with shorter, compact canopy sails can and do withstand significant storms like the one in 1987. Above top; a sample of Ted Green’s post-storm map assessing the damage to trees in Windsor Great Park. Above: Veteran tree sites in the south-east. (Map data © Google) Above; The Royal Oak at Richmond park Above; Pollard beech at Burnham Beeches. Above; King Offa’s Oak in Windsor Great Park, all 3 are good examples of ancients/veterans that withstood the 1987 storm. The case studies that follow examine two Hampstead Heath veterans that survived the storm. Both trees have benefited from management intervention. Case study 1: The Bandstand Oak In the heart of a north London Victorian park known as Golders Hill sits a well-known landmark tree called the Bandstand Oak (above). Thousands of people have sat in their deckchairs during the summer months over many decades listening to jazz and watching clowns hosted at the park’s performing stage. The oak tree is thought to be approximately 450 years old and has a girth of 6.75m. I first became aware of this particular tree as a child when my family visited the park and Hampstead Heath around the late ’70s and early ’80s. The two images below taken in 1900 and 1975 appear to show the tree had been thinned and/ or pruned but they may also reveal what years later I would understand to be early natural retrenchment. It is an imposing landscape tree that is a relic of a less urban time in the site’s history. It had changed little in terms of aesthetics and health since the beginning of the 1900s up to when the storm struck. I take many images of trees daily, both at work and in my leisure time, so it is a little frustrating that I didn’t capture any images of this tree in the immediate aftermath of the storm. We didn’t have digital cameras back then and were too busy clearing up damaged trees across the site and unblocking the roads outside. The tree is open-grown and sits on a hill so the wind had complete access to wreak havoc on the canopy. I suspect that the oak was then, as now, colonised by the brown rot decay of the chicken of the woods (Laetiporus sulphureus) and this would have had a significant influence on the oak being dismantled branch by branch as opposed to being completely uprooted. The ferocity of that storm and the heartwood decay resulted in the upper crown becoming smashed and fractured. The crown was subsequently cleaned and made ‘safe’ by being reduced back to almost just the trunk and stubbed main scaffolds. At that time, the knowledge of retaining as much photosynthetic material as possible whilst reducing a veteran tree (post storm or otherwise) was perhaps in its infancy and the guys on the tree team had a very long list of trees to clear up Although the images at the top of the article and above were taken several years after the work, the tree’s winter frame allows us to see the severity of the reduction carried out at the time of the storm in comparison to the tree as it was in the earlier photographs. Clearly visible in the sunrise image is how well the tree has responded to the ‘topping’ over that time. The reiterated branch framework has developed well in the last 30 years due to the oak’s vitality. The only canopy work done in the last 15 years has been to retrieve a succession of lost kites and the removal and/or partial removal of significant-sized dead branches above static park benches. With time and an understanding of the niche habitat that retained dead branches provide for biodiversity, we managed the risk of the sitting target by moving the ‘static’ benches and erecting a metal fence which in keeping with the park’s boundary fencing. This has also had the benefit of stopping young aspiring monkeys who loved to climb the old tree and were damaging the bark and lower branches. Those future potential arborists still have younger trees to climb on as several young oaks were planted before and after the storm to continue the oak population that has been part of the local historic treescape for centuries. The tree does suffer root issues which can be seen in the decline on one side of the canopy. This is due in part to the close-cropped grass-mowing regime and the compaction caused by heavy foot fall – this is a popular, well-used park. The demand for space during good weather and events held at the bandstand limits the total area of roots we can protect with the fencing. The tree has had on-going applications of foliar microbial compost tea which it is hoped will benefit the health of the oak and the soil below. It remains an imposing landscape feature tree now and hopefully for many decades to come. Case study 2: The hollow beech This hollow beech has a girth of 5.52m girth at 2m. It mostly withstood the 1987 storm and also subsequent arson attacks. It has been hollowed out by the activity of bacteria and various decay fungi over the last 100 years or so. The storm stripped bare most of the upper canopy, leaving no upper trunk beyond 13m and only six of the main scaffold branches that make up the remaining framework. Surprisingly for beech, over the next three decades the tree has reiterated a new canopy, forming dozens of new ‘young trees’ on the upper branch surfaces. The beech is subject to a reduction cycle where it is reduced in height by 1–2m every five years with the intention of keeping the canopy from protruding out beyond its neighbours and having the younger, weakly attached pole regrowth exposed to wind load. Habitat created by natural and unnatural events Storms of course are not the only major risk to veteran trees. The veteran pollard oaks at Ashtead Common (below) largely survived the great storm of 1987, unlike the maiden beech and other species in the locality that were swept over in their hundreds, many of them succumbed to a large (bracken) fire in 1990 which damaged or destroyed over a hundred of the old pollards. Those trees are no longer alive. However, they still provide valuable habitat as standing dead wood volume for a wide range of saproxylic invertebrates, fungi, bats and birds. Maintaining these standing dead wood volumes is an important aspect of biodiversity management. For more information on this habitat-type creation and retention, see the authors article ‘Standing dead trees in the urban forest’ in the ARB Magazine 166 (autumn 2014). Storms, pruning and other events like mechanical injuries help create veteran features and improve potential habitat value for biodiversity. As long as assessment of the loss of part of the tree can determine that there is no adverse effect on its stability, these tears, branch socket cavities and impact wounds can be retained as future habitat. The Bandstand Oak has been a regular host to kestrels and to smaller avian species like nuthatch and blue tits. Cavities in the trunk and branch unions from pruning and natural branch tear outs provide fine habitat potential that is utilised by successive generations of birds and bat species. The Moccas Park oak, below top, has been left unmanaged because it sits in a very rural landscape with low risk to site visitors whereas the Hampstead oak pictured below bottom (which is colonised by Fistulina hepatica) has been lightly reduced to mitigate load on its canopy sail as it sits in an urban open space with many visitors. Fungi species like Laetiporus sulphureus, Fistulina hepatica and Buglossoporus quercinus are just some of the organisms at play in the slow decay process of wounds ; species like owls eventually take advantage of these sites and colonise them. The decay process can take many decades in temperate areas like northern Europe. Bees, woodpeckers, owls and other species all accelerate the process of cleaning out cavities for their own use. . Igive great thanks to Ted Green who continues to inspire and also helped with information regarding the veteran and ancient trees at Windsor Great Park before and after the great storm. This article was originaly published in the ARB MAgAzIne | Issue 178 Autumn 2017 View full article